Master
From AssaultCube
The master is the player in charge of controlling the server. If a master is present, his or her name will be highlighted in green on the scoreboard. A master is able to control the server by switching gamemodes and maps, kicking and banning players, changing the master mode, using forceteam to switch a player's team, and clearing the ban list with the removebans command.
Version 0.93 will be the last version to feature a master system. Newer versions will use a voting system in its place.
You can use the setmaster command to become the server's master by setting its value to 1 (setmaster 1). For another player to claim master status, the current master must resign (setmaster 0) or leave the server.
Dealing with problematic masters
If a cheater or other problematic player has master, leave the server immediately. Unless you have the server's admin password, there is no way to take master away from the cheater. Staying in the server to insult the cheater or complain about his or her cheating will only encourage the cheater to continue. Disconnect from the server and go to a server with a better master, or a server where the master status is still available for you to claim. Staying in the server will only provide the cheater with players to cheat against, and more players will continue to join when they see a server with players in it.
If you know the server's admin password, you can login as admin to remove a player's master status, and also ban the bad master if desired.
Prevention of problematic masters
Whenever you connect to a server, look at the scoreboard (Tab key by default) and see if anyone else is highlighted in green. If nobody is, use the setmaster command to become the master. Even if you don't need it for anything yet, it's safer to claim it now so no bad players can claim it later.
When setting up a server, you have the option of specifying an admin password with the -x parameter. Using the password example, the parameter and its argument (in this case, the password) would look like -x"example". The quotation marks on each side of the password are not necessary if you're not using spaces in your password, but using them makes it easier for you to distinguish between the parameter and the password, especially when using an editor with syntax highlighting.
If you're a server owner, it may be a good idea to share your admin password with trusted players (friends, clan members, etc.), so they're able to get rid of problematic masters while you're not available.

